Distraction arthroplasty of the hip by bicentric femoral head prosthesis.

Distraction arthroplasty of the hip with bicentric femoral head prosthesis was performed on 18 hips with advanced secondary osteoarthritis. This method of hip arthroplasty consists of reconstruction of the deformed acetabulum into the dome-shaped acetabulum, replacement of the femoral head by the bicentric femoral head prosthesis, and postoperative continuous long-axis traction to the lower extremity. Postoperative physical therapy is performed on the assumption that the articular cartilage is formed in a narrow empty space between the articular surfaces made by continued application of distraction to the hip. In distraction arthroplasty, the hip may regain a wide range of painless motion. Roentgenographically, the dome-shaped acetabulum was covered by a narrow radiolucent zone backed with a dense bone plate. The functionally remodeled structure of the hip was maintained during the follow-up period of six months to four years 11 months.